package com.forenow.demo.JDBCdemo;
import java.sql.*;
public class JDBCtest {
    static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/test?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
    static final String USER = "root";
    static final String PASS = "123456";
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try{
            // 注册 JDBC 驱动
            Class.forName(JDBC_DRIVER);

            // 打开链接
            System.out.println("连接数据库...");
            conn = DriverManager.getConnection(DB_URL,USER,PASS);

            // 执行查询,获得statement对象
            System.out.println(" 实例化Statement对象...");
            stmt = conn.createStatement();
            String sql;
            sql = "SELECT * FROM student";
            ResultSet rs = stmt.executeQuery(sql);

            // 展开结果集数据库
            while(rs.next()){
                // 通过字段检索
                int id  = rs.getInt("id");
                String name = rs.getString("name");
                String sex = rs.getString("sex");
                int grade=rs.getInt("grade");
                String phone=rs.getString("phone");
                String email=rs.getString("email");

                // 输出数据
                System.out.print("学生id "+id+"\t学生姓名 "+name+"\t学生性别 "+sex+"\t学生成绩 "+grade+"\t学生电话 "+phone+"\t学生邮箱 "+email);
                System.out.println();
            }
            // 完成后关闭
            rs.close();
            stmt.close();
            conn.close();
        }catch(SQLException se){
            // 处理 JDBC 错误
            se.printStackTrace();
        }catch(Exception e){
            // 处理 Class.forName 错误
            e.printStackTrace();
        }finally{
            // 关闭资源
            try{
                if(stmt!=null) stmt.close();
            }catch(SQLException se2){
            }// 什么都不做
            try{
                if(conn!=null) conn.close();
            }catch(SQLException se){
                se.printStackTrace();
            }
        }
        System.out.println("Goodbye!");

    }

}
